Chater 47 & 51 Flashcards
How long should you wait before you separate a model from the impression?
45-60 mins
When pouring an impression where do you begin placing the gypsum material in a mandibular impression?
Posterior tooth to the right
List the 2 parts of the dental model?
Art and Anatomic
How are gypsum material mixed?
Bowl and spatula
When mixing gypsum materials, how are the powder and water incorporated?
Powder to water
How many types of gypsum products do we have in dentistry? Name them.
- Dental plaster
- Dental Stone
- High strength stone
What is another name for dental model?
Study cast
What type of wax is used to form a wall around a preliminary impression when pouring it up?
Boxing wax
Acrylic resin for the fabrication of trays is supplied as:
Liquid + powder
What type of custom tray is made for a vital bleaching procedure?
Thermo plastic resin
Of the three types of custom trays discussed which technique use a volatile hazardous material?
Acrylic resin tray
What specialty practises might have a more expensive laboratory?
Ortho, prosthodontist, paediatrics
Which would be an example of a contaminated item commonly found in the dental laboratory?
Impression
What piece of equipment is used to grind away plaster or stone?
Dental model trimmer
The size of a wax spatula most commonly used in the lab is a #____
7
What piece of equipment does the dentist use to determine centric relation from a diagnostic model?
Articulator
Which of the two models do you begin trimming first?
Maxillary
What is the one specific area on a dental model where the maxillary and mandibular model is trimmed differently?
Anterior portion
What should be placed between the two models when trimming them together?
Wax bite
This material is a mixture of gypsum and water used in the finishing of models when voids are present:
Slurry
To extend an impression tray what wax is used?
Utility wax
What type of wax is used to get a patient’s bite?
Baseplate wax
What is placed to prevent a tray from sitting too deeply onto the arch or quadrant?
Utility wax
How are dental impressions cared for before they are taken to the dental lab?
Disinfected, washed off and labelled
With Alginate impressions how long should you wait before pouring the impression?
Only 1 hour because it will dry out
Four examples where dental models can be useful for dental procedures?
- visual presentation of dental treatment
- fixed or moveable prosthetic device
- Orthodontics appliances
- production of custom trays
What is the main purpose of the vibrator?
To get rid of air bubbles
How fast can your laboratory handpiece go?
20,000 RPM
Your vacuum form can be used to do what type of dental product?
Bleaching tray and custom fluoride tray
When would the use of the sandblaster be needed in the dental lab?
Crown and dentures
How many methods of pouring do we have in dentistry? Name them
- invert a poor
- double pour
- Box pour
What is double pour?
Anatomic first, set new mix then art portion
What is Inverted poor?
One mixture both anatomic + art
What is a Box poor?
Make a small box and pour up
What are five laboratory rules?
1- no eating or drinking 2- wear all PPES 3- hair up 4-report all incidences 5- stays clean
What type of procedures will be performed in a dental laboratory?
Making a dental model, trim and finish and custom tray
What does the anatomical portion of the dental model consist of?
Teeth, oral mucosa, muscle attachment
What should you do to your model before you start trimming?
Wet or soak
When turning on your model trimmer what do you need to make sure you do before you start trimming?
Turn on water
Which material is used to construct a custom tray?
Acrylic resin, thermaoplastic, light cured
What do you do to prevent walking on a provisional restoration?
Vaseline
What are the powder/water ratio of the 3 gypsum products?
Plaster – 100 g to 45-50 water
Regular stone – 100 g to 30-32 water
High stone – 100 g to 19-24 water
Which type of chips and is commonly referred to as plaster of Paris?
Model plaster
What type of inly wax is used for indirect wax patterns on dies?
Type B
Which type of wax is used to cover orthodontic brackets?
Utility wax
Another name for a dental model is?
Dental cast
What dental material is used in the creation of a dental model?
Gypsum
How was self-cured acrylic resin supplied for the fabrication of custom trays?
Powder and liquid
What technique is used as a volatile hazardous material?
Acrylic resin
